Currently, carbon quantum dots have attracted considerable attention due to their unique properties and desirable advantages. High crystallinity, water solubility, good dispersibility, small size, low toxicity, inexpensive raw materials, high chemical stability, environmental compatibility, low cost, stability under light, desirable charge transfer with advanced electronic conductivity, as well as specific thermal and mechanical properties are some of these features. Carbon quantum dots have various applications in different fields. Fabrication of precise chemical and biological sensors, bioimaging, solar cells, drug tracking, nanomedicine, light-emitting diodes (LEDs), and electrocatalysts are some of these applications. Biological sensors based on carbon quantum dots are capable of detecting various metal ions, acids, proteins, biotin, polypeptides, DNA and miRNA, water pollutants, hematin, drugs, vitamins, and other chemicals. In the present study, the properties of carbon quantum dots and some of their fabrication and applications methods have been addressed. In continuation of the paper, the effect of carbon quantum dots on important factors in plants such as growth and development, photosynthesis, absorption and transportation of substances, resistance to biotic and abiotic stresses, as well as their application in agriculture has been investigated.

A noninteracting quantum-dot arrays side coupled to a quantum wire is studied. Transport through the quantum wire is investigated by using a noninteracting Anderson tunneling Hamiltonian. The conductance at zero temperature develops an oscillating band with resonances and antiresonances due to constructive and destructive interference in the ballistic channel, respectively. Moreover, we have found the number of antiresonant exactly depends on the number of quantum dot in every array and increasing array make antiresonants wide increase.

Quantum dots (QDs) are nanoparticles (NPs) with electronic and optical properties such as emitting bright light and fluorescence. They also carry specific characters such as photostability, high quantum yield, high emission, and size-turnable. Nowadays, a great interest is given to the extensive use of theranostic-NPs for sensing and imaging, as well as drug delivery. Moreover, QDs may yield great potential for the diagnosis and treatment of various central nervous system (CNS) diseases (e. g., Parkinson’, s disease, Alzheimer’, s disease, and multiple sclerosis). The blood-brain barrier (BBB) protects the brain tissue. Only certain small molecules like water and gases can cross BBB, whereas larger molecules enter via receptors, but many drugs are incapable of passing the barrier. A series of great advances have been achieved concerning using different NPs (e. g., QDs) to deliver drugs to the brain and CNS imaging. In this review, we discussed a wide variety of QDs along with their production, passive or active delivery of therapeutic agents for neurodegenerative diseases, and different image production.

Quantum Dots are a group of semiconductors nanomaterials whose size is about less than 10 nm exhibiting unique optical and electric properties which impart different advantages in terms of wide and continuous absorption spectra, narrow emission spectra, high quantum yield, long fluorescence lifetimes, and high photostability. Based on the unique properties of quantum dots have a variety of applications. This review informs about quantum dots structure, properties of quantum dots, surface modification of quantum dots for biocompatible, synthesis process and its important application like labeling cell structure and FRET (Fluorescence resonance energy transfer). Quantum dots as bio-sensors, bio-marker, and bio-imagine are used in many therapeutic systems. Several attractive applications have been observed with supramolecular compounds: Calix-4 arenes derivatives with quantum dots in the field of medical science.

In this paper, pyramidal shaped GaN-based quantum dots (QDs) with different sizes in each layer, surrounded by 𝐴 𝑙 0. 2𝐺 𝑎 0. 8𝑁 is proposed for infrared photodetector mainly to enhance the detector performance. In this model, we are considering the QDs sizes’ distribution to calculate all parameters instead of using Poisson distribution to express the inhomogeneous broadening just in the absorption coefficient. To model the performance of the devices, the Schrö dinger equation has been solved using the effective mass approximation; then, the absorption coefficient, the gain, the responsivity, the electron mobility, the dark current, and the detectivity as a function of temperature for different biases are obtained. Significant improvements in the optical behavior are seen in the modeled results at T = 220 K.